Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) can be used to set up Point-to-Multipoint (P2MP) and Multipoint-to-Multipoint (MP2MP) Label Switched Paths (LSPs). The set of LDP extensions for setting up P2MP or MP2MP LSPs may be referred to as multipoint LDP (mLDP), which may be specified in Internet Engineering Task Force (IETF) Request for Comments (RFC) 6388, titled “Label Distribution Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths,” which is hereby incorporated by reference. Certain targeted-LDP (T-LDP) protocols may be used herewith according to RFC 5036, titled “LDP Specification” and RFC 5561, titled “LDP Capabilities,” which are hereby incorporated by reference.
In order to meet user demands, operators and service providers continue to deploy multicast applications using mLDP across MPLS networks. In certain key scenarios, conventional Internet Gateway Protocol (IGP)-mLDP convergence mechanisms fail to meet protection switching times required to minimize, or negate entirely, application interruptions for real-time applications, including stock trading, on-line games, and multimedia teleconferencing. Often, service protection paradigms include a pre-computation and establishment of a backup LSP. Once a failure has been detected on the primary LSP, the traffic may be transmitted across the backup LSP.